Intravascular occlusion coils are used to form blockages within the vasculature for controlling internal bleeding, treating aneurysms, or reducing blood flow to tumors. These coils are typically placed at the site of the desired blockage by means of a catheter.
Several patents describe occlusive devices that include strands or fibers. U.S. Pat. No. 5,226,911 describes a helical metal coil that has one or more fiber bundles having a serpentine configuration, the loops of which extend about the individual windings of the coil. U.S. Pat. No. 5,417,708 shows a helical coil that has Dacron fibers extending radially from the coil windings. FIG. 5 of U.S. Pat. No. 5,423,849 describes a vasooclusive device composed of a tube made of braided radiopaque fibers having a bundle of radiolucent fibers extending axially through the lumen of the braided tube. The ends of the fibers that form the bundle may be heat sealed.